#include<bits/stdc++.h>
using namespace std;
typedef double db;
const db eps=1e-6,pi=acos(-1);
db X,Y,L,W;
db solve(db theta)
{
	return (L*sin(theta)+W/cos(theta)-X)/tan(theta);
}
int main()
{
	while(scanf("%lf%lf%lf%lf",&X,&Y,&L,&W)==4)
	{
		db l=0,r=pi/2.0;
		while(r-l>eps)
		{
			db mid1=(l+l+r)/3.0,mid2=(l+r+r)/3.0;
			if(solve(mid1)>solve(mid2))r=mid2;
			else l=mid1;
		}
		if(solve(l)<Y)puts("yes");
		else puts("no");
	}
	return 0;
}
